Friday, October 5, 2012

Fluid cathedrals: Gels under the microscope

Professor Michael Solomon and doctoral student Lilian Hsiao, both in chemical engineering, discuss the architectural structures revealed by the 3D map of particles inside a gel. Image credit: Laura Rudich.

A dollop of hair gel might not look like much, but Michigan Engineering researchers have found that it's a labyrinth of chambers and domes, constructed by the particles inside. These structures allow the gel to hold its shape and determine how much pressure it can withstand before it starts to flow.

While manufacturers currently use trial and error to develop gels with a particular degree of solidity, this discovery could provide a way to design gels for particular applications.

Friday, August 10, 2012

Could flowing liquid batteries be key to a renewable grid?

Aaron Shinkle, a graduate student in the group of professor Charles Monroe, prepares a liquid battery test cell. Photos by Joseph Xu, College of Engineering Communications.

So-called flow batteries could be the answer to storing solar, wind, and other renewable energy on the scale that power companies need, but it will take engineers and scientists to get them to that level.

“People say they’re putting a solar panel on their house,” said Charles Monroe, professor of chemical engineering. “They don’t say they’re putting a gigantic battery in their attic.”

But if homeowners want to get the most out of those solar panels, they had better install a means to store the energy they harvest. And that’s just the small version of the problem – as renewable energy sources integrate with the grid on a large scale, batteries fit for power stations are a crucial piece of the puzzle.

With current lithium-ion technology, batteries the size of semi-truck trailers can hold 500 kilowatt hours (kWh) – or enough to power about fifteen US houses for a day. Unfortunately, they degrade somewhat with each recharge and survive for only about a thousand recharges. In order to develop batteries that can hold as much energy as lithium-ion designs and also last for many years, Monroe’s team has joined forces with that of Levi Thompson, a fellow professor of chemical engineering.

Wednesday, June 20, 2012

Bolt from the blue in the plasma lab

A mod on the underwater plasma jet experiment turned up some unexpected chemistry.

Photo by James Rotz, Michigan Engineering
It grew invisibly in the darkened laboratory, lit only by the thimbleful of plasma that glowed purple in a beaker of water. Nuclear Engineering and Radiological Sciences (NERS) graduate student Ben Yee had turned out the lights, shaded the windows, turned off the computer monitors so that the detector would only pick up the light from the plasma. After half an hour of taking data, he turned off the plasma and turned on the lights to find that a mysterious blue jelly had taken up residence in the bottom of the beaker.

It sounds like an alternate beginning for the 1950s horror flick The Blob, but Yee isn’t worried. “I haven’t heard of any unusual deaths or missing persons in the past few days,” he said. Lifting a beaker from another trial of the experiment, he studied the algae-like green jelly at the bottom. “It seems peaceful. Family-friendly,” he added. So, Flubber’s lazy cousin?

Tuesday, June 19, 2012

Senior citizens behind the wheel

Older drivers get hurt worse in crashes. A Michigan Engineering professor thinks their posture and body shape may play a role. We visit the U-Mich crash lab to learn more about the study. E9XPTV3FVPB7

Crash test dummy
A mid-sized male crash test dummy prepares for a test in the
University of Michigan Transportation Research Institute's sled lab.
Photo by Laura Rudich

There’s something curiously morbid about crash test dummies. They have an unnerving combination of lifeless and life-like features.

They even wear shoes in the sled lab at the University of Michigan Transportation Research Institute—brown oxfords for the mid-sized male model on deck for a head-on collision at 30-mph.

“We want the tests to be as realistic as possible,” explains Matt Reed, research associate professor at UMTRI and in industrial and operations engineering.

But there’s only so much Reed and his colleagues in the field can do right now. The federal government tests crash protection for adults with just two dummy sizes, an average man and a small woman. Many people don’t fall into one of these categories. So Reed is working to get a more accurate picture of American drivers and passengers.

Right now, he’s studying older drivers. He has found that they tend to fare worse than younger people in crashes of the same severity. A lot of factors are likely to blame, Reed acknowledges, but he’s zooming in on a couple that might be easier to affect—seatbelt fit and driver posture. His team is also measuring body shape with a special 3D scanner. Reed says there’s never been a systematic study like this. All summer he and his team, which includes eight engineering undergrads, are measuring people.

Friday, June 8, 2012

U-M engineers visit Japan, offer aid

From the left, Yutaka Watanabe, Ron Gilgenbach, Zhong He, and Akira Hasegawa. Watanabe and Hasegawa are professors at Tohoku University. Hasegawa explains the devastation of the tsunami in Yamamoto city.  (Photo courtesy of Yugo Ashida)

Just over a year after Japan raised the Fukushima accident to the highest rating on the International Nuclear Event Scale, three members of the Nuclear Engineering and Radiological Sciences (NERS) faculty travelled to Japan to forge new relationships with some of the country’s leading engineers and energy policy-makers.

Professor Ron Gilgenbach, NERS chair, returned optimistic about recovery around Fukushima and the possibility that Michigan Engineering expertise could be of some service. He told LabLog about some of the highlights from Tokyo, the Miyagi Prefecture, and Fukushima City.

Monday, June 4, 2012

U-M radiation detectors go the distance

A contingent of the Detection for Nuclear Nonproliferation Group travelled to Italy to test their detectors for catching bomb-makers.

Angera Castle of Ispra, Italy, is alright, but you should see the local nuclear laboratory. (Photo courtesy of Eric Miller)

When Professor Sara Pozzi of the U-M Department of Nuclear Engineering and Radiological Sciences and her team visit the idyllic town of Ispra, Italy, just south of the Alps on the shore of Lake Maggiore, they don’t come for the food or the scenery. They come for the plutonium.

Along with certain types of uranium, the US government designates plutonium as a “Special Nuclear Material” because in great enough quantities, it could be used to make a nuclear bomb. These materials are carefully controlled, and Pozzi’s Detection for Nuclear Nonproliferation Group (DNNG) is trying to keep it that way. They develop detectors to spot these materials. “You would put them in airports and commercial ports of entry, where ships come in. You can imagine the difficulty of having to scan big cargo containers,” Pozzi explained.

Universities aren’t high-security sites that can keep uranium and plutonium on hand for testing detectors, so in April, Pozzi and two of her graduate students, Jennifer Dolan and Eric Miller, tested detectors at the European Commission’s Joint Research Center, of the Institute for the Protection and Security of the Citizen, in Ispra.

Monday, May 21, 2012

Real-world tests for Polaris radiation detector

An invention from the College of Engineering promises to make radiation imaging more portable, with the potential to catch nuclear terrorists, improve safety in nuclear power plants, and map out radiation contamination following accidents like Fukushima.

Weiyi Wang points out a gamma ray interaction in the 18-crystal Polaris detector, shown on the screen of the attached computer almost in real time. Polaris software narrows down the origin of a gamma ray to a cone.
Just over a year ago, Professor Zhong He and members of his research group in the Department of Nuclear Engineering and Radiological Sciences formed the company H3D to commercialize their radiation imager. Unlike other radiation detectors on the market, theirs can run at room temperature – rather than -321°F – and it can also show where radiation is coming from.

The imager sees the world in gamma rays, which are like rays of visible light but with up to about a million times more energy. It contains crystals of very pure semiconductor that absorb the gamma rays, measuring their energies. The energies of the gamma rays emitted by a radioactive material are like a bar code, giving away its identity.

To figure out where a gamma ray is coming from, the detector looks at the way it bounces off an atom before being absorbed. The software can work out the angle of the bounce, which narrows down the gamma ray’s origin to a cone. After measuring several gamma rays, an intersection point appears – or perhaps more than one intersection, if gamma rays are coming from multiple places.

Monday, April 23, 2012

The world's first two-legged robot with a trip reflex

The two-legged robot named MABEL can now recover from a stumble like a person, making her the world's first robot with a trip reflex, University of Michigan researchers say.

The fastest bipedal robot with knees can now step up onto a platform that's in her path. She has no cameras, so she uses a sense of touch, so to speak, to keep steady footing.

"No other bipedal robot out there could do this, and I am pretty sure that most people would face plant as well," said Jessy Grizzle, a professor in the Department of Electrical Engineering and Computer Science and MABEL's creator.

Hae Won Park, a doctoral student in the Department of Electrical Engineering and Computer Science (who defended his thesis last week), programmed the robot to operate in this way. First, he researched the literature on how humans use their feet to catch themselves from falling. People have two different strategies, Park explains. If they stumble early in the swing phase of a step, they quickly lift that leg. If they trip late in the step cycle, they abruptly lower the swing leg and then raise the other.

The researchers added sensors to the front of MABEL's legs to give her a better feel for what she's encountering. With this added sensory information and some brand new algorithms, the bot can now keep solid footing in the face of a four-inch platform. She plants right on top of it.

MABEL has been walking well on level ground since summer 2009. She took up running in August 2011 and later that year could step down, without warning, from an 8-inch height without falling. A standard US stair is 7 3/4 inches. In her latest video, she shows off several of these skills as she
saunters deftly through an obstacle course of boards.

This research could pave the way for two-legged robots that perform rescue missions. Such robots would need to be able to walk up and down stairs, step over toys on the floor of a burning house, for example, or navigate through rocks in a war zone. These ideas aren't far-fetched. Just last week, DARPA announced a $2 million Robotics Challenge for a disaster-response bot that can aid in a nuclear emergency scenario. Here's how the New York Times explains the contest:
...(T)he Defense Advanced Research and Planning Agency, or Darpa, lists eight likely tasks the robot will need to perform — among them driving a vehicle to a simulated disaster site, moving across rubble, removing rubble from an entryway, climbing a ladder, using a tool to break through a concrete wall, finding and closing a valve on a leaking pipe, and replacing a component like a cooling pump.
To be continued....

Monday, March 12, 2012

The sound of a solar storm, and a tour of "audification"

A composer and NASA fellow at Michigan Engineering is turning satellite measurements into sound as a new data mining approach. Here's a demonstration.

It does sound like stardust. That, with maybe a little electronic whale song mixed in.

This "sonification" of some of the most recent solar storm activity illustrates a unique new approach to data mining in the University of Michigan's Solar and Heliospheric Research Group. Its creator is Robert Alexander, a design science Ph.D. student on a NASA fellowship to explore how turning data into sound could help scientists hear patterns or anomalies that their eyes might miss.

For this project, Alexander started with 90 hours worth of raw information from two NASA spacecraft, MESSENGER at planet Mercury and the Solar and Heliospheric Observatory near Earth. (The instrument he used from MESSENGER is the Fast Imaging Plasma Spectrometer, or FIPS, built right here at Michigan. It's said to be the first to register the latest storm.)

In the particular type of sonification he employs, called audification, each data sample becomes a single audio sample. That means 44,100 pieces of information play back as one second of sound at the common sampling rate of 44,100 hertz. So to make sense of the audio and extract anything meaningful from it, Alexander has to stretch it and in this case run it through additional algorithms.

It's a groundbreaking process that he and his colleagues say is giving rise to a new research tool.

"I can listen to a million data points in approximately 22 seconds," Alexander said.

Last year, this technique led to a new discovery: It turns out that a particular ratio of carbon atoms that scientists had not previously keyed in to can reveal more about the source of the solar wind than the ratios of elements they had currently relied on. He's the second author on the paper published in December in Astrophysical Journal.

Alexander, the Solar and Heliospheric Research Group's data sonification specialist, emailed me a detailed explanation of this work, complete with audio snippets. I think it's all worth sharing.
Before you proceed, pull out a nice pair of headphones and set your volume to a very low level.
For starters, have a listen to the heart-beat of the sun, a sound file which I generated by translating 47 years worth of solar proton speed data directly to audio. What we're listening to here is a flow of charged particles called the solar wind.